In the United States and Canada, weather alerts and emergency information are broadcast over the Weather Band, consisting of seven channels from 162.4 to 162.55 MHz. Weather alerts employ Frequency Modulation (FM), and the messages consist of voice alerts that are time-multiplexed with Frequency-Shift Keying (FSK)-modulated digital data, carrying information about the nature and geographical relevance of the alerts. While both FM radio and Weather Band transmissions employ frequency modulation, the message structure for Weather Band alters is very different from FM radio and a standard FM receiver is not configured to receive and detect alerts in the Weather Band.